html,
body {
  height: 100%;
}

* {
  box-sizing: border-box;
}


nav,
main {
  transition: -webkit-transform 150ms ease-out;
  transition: transform 150ms ease-out;
  transition: transform 150ms ease-out, -webkit-transform 150ms ease-out;
}

nav {
  z-index: 100;
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  width: 16em;
  background-color: #353441;
  -webkit-transform: translateX(-16em);
          transform: translateX(-16em);
}
nav.menu-active {
  -webkit-transform: translateX(0);
          transform: translateX(0);
}
nav.menu-hover {
  -webkit-transform: translateX(-15em);
          transform: translateX(-15em);
}
nav h1 {
  z-index: 100;
  display: block;
  position: absolute;
  top: 0;
  right: -60px;
  height: 60px;
  width: 60px;
  line-height: 60px;
  font-size: .8em;
  font-weight: 800;
  letter-spacing: 1px;
  color: #9DC6D1;
  text-transform: uppercase;
  text-align: center;
  background-color: #353441;
  cursor: pointer;
}
nav h1:hover {
  color: #353441;
  background: #fff;
}
nav ul {
  margin: 0;
  padding: 0;
}
nav li {
  display: inline-block;
  padding: 0 1em;
  width: 100%;
  height: 60px;
  color: #9DC6D1;
  line-height: 60px;
  background-color: #353441;
}
nav li:nth-of-type(2n) {
  background-color: #3a3947;
}
nav li:hover {
  background: #fff;
}

main {
  z-index: 0;
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  display: flex;
  align-items: center;
  overflow: hidden;
  background-color: #9DC6D1;
  -webkit-transform-origin: 0% 50%;
          transform-origin: 0% 50%;
}
main:after {
  content: '';
  display: block;
  position: absolute;
  z-index: 1;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  background: linear-gradient(to right, rgba(0, 0, 0, 0), rgba(33, 33, 45, 0.5));
  visibility: hidden;
  opacity: 0;
  transition: opacity 150ms ease-out, visibility 0s 150ms;
}
main.menu-active {
  border-radius: .001px;
  -webkit-transform: translateX(16em) rotateY(15deg);
          transform: translateX(16em) rotateY(15deg);
}
main.menu-active:after {
  visibility: visible;
  opacity: 1;
  transition: opacity 150ms ease-out, visibility 0s;
}
main.menu-hover {
  border-radius: .001px;
  -webkit-transform: translateX(1em) rotateY(1deg);
          transform: translateX(1em) rotateY(1deg);
}
main section {
  position: absolute;
  top: 0;
  left: 0;
  bottom: 0;
  right: 0;
  margin: auto;
  padding: 1em 4em;
  max-width: 680px;
  overflow: auto;
  background-color: rgba(255, 255, 255, 0.5);
}

section h1 {
  font-weight: 800;
  text-transform: uppercase;
  font-size: 2em;
}
section p {
  display: inline-block;
  margin: 16px 0;
}